What Is a TWAIN Driver Anyhow?

Commonly referred to as “technology without an interesting name,” TWAINs are a very important. Yet it’s unknown technology in the imaging industry. DentiMax Imaging Director Jim Ramey explains what a TWAIN driver is.

TWAIN, put simply, is a protocol that allows an imaging device to acquire an image (initially flat-bed scanners). It saves that image directly into a “TWAIN compliant” imaging software application. This is needed in order to use that image (such as Photoshop).

There’s quite a bit more to it these days. But initially this is what exactly the TWAIN protocol was designed for.

Where “TWAIN” Came From

In the early 1990’s, dental practices found it so very difficult to get a scanner to communicate with a PC. It also involved the scanner acquiring images into the applications that everyone wanted to use these images in. Even file types didn’t receive standardization yet. Many scanner companies had their own “proprietary” image files. And that could only work with the software they made and created by the devices they made!

Back in 1992, representatives of some of the largest companies in the imaging industry got together. Their intention involved standardizing the communication between the imaging software and the hardware that created those images. They created the TWAIN Working Group and developed the initial toolkit in 1992. Since then, updates occur every so often. The last one occurred in 2015.

Defining what TWAIN meant

They set the word TWAIN itself in all caps to make it stand out from other “tech speak” coming out at the time. This lead many to believe that this word was an acronym. And the acronym theory persists even to this day. One of the most common definition calls it “Technology Without an Interesting Name.” Some even wrote this as the “official” meaning of the word.

However, this is not correct. The official website for the TWAIN working group states that the first name they chose was already taken, so they chose TWAIN based from the phrase “never the twain shall meet” (it also means “two” – which is an imaging hardware device and an imaging software application being connected). The official meaning of the chosen term TWAIN, also referenced the extreme difficulty that devices like scanners had in the early 90’s communicating with the image applications that were designed to work with those acquired images.

The Anatomy of a TWAIN

TWAINs are created and maintained by the manufacturer of the imaging device. If you purchase a digital camera, the TWAIN should always come with the camera or it will be able to be downloaded from the manufacturer’s web site. Imaging applications (such as Photoshop) do not have or maintain any TWAIN drivers. There are simply too many devices that can acquire images for any image software company to keep and maintain a library of every device that could possibly acquire an image to be used in their software. This is an industry standard. You will always go to the manufacturer of the device you are using to get the TWAIN for it.

Many TWAINs have an interface, or a screen that allows the end-user to preview the image they are acquiring from the device the TWAIN works with. The “calling application” is what the image management software is referred to when you are talking about TWAINs. The image software “calls” the TWAIN driver, which will initiate the acquisition from the imaging device. If there is an interface, this will be launched. Or, as with a scanner, you would simply push the scan button (with other devices, the acquisition process will differ slightly. Refer to the device manual or technical support from the manufacturer of the device.) It acquires the image and returns it automatically to the calling application. From there you can save the image and do whatever you need to do with the newly acquired image!

Not Quite a Driver

Lastly, with all TWAINs in general, even though they get referred to as “TWAIN drivers,” they don’t work as an actual driver for a device. All of the imaging devices require a “device driver,” this is the initial installation that lets the Operating system (like Microsoft Windows) to “see the device” and recognize the device as what it is (such as a scanner, a camera, or a digital intraoral sensor). The TWAIN needs to have this device driver in order to communicate with the device.

The TWAIN will not work if the computer cannot “see” the device before the TWAIN driver is installed. Another way some people think of the TWAIN is that it is a “translator” so that whatever type of image that you are acquiring from whatever type of device, the TWAIN will allow that device to capture and save directly into the imaging software that you are working with, “translating” between the device and the software so they are able to communicate with each other directly.

The TWAIN Working Group maintains the TWAIN SDK and API which companies all over the world use to this day in order to develop their TWAIN drivers to be able to capture images with their devices and save them into any TWAIN compliant image software application.

With Digital Dentistry, TWAIN Comes Into Play With Many Devices

Digital panoramic/cephalometric units:

Every one of these devices has a TWAIN which will allow practices to capture the images into whatever imaging application your practice is using. The digital pans, especially early on, were FAR too expensive for the manufacturers to tell practices what imaging software they needed to capture images. This explains why the digital panoramic units all have a TWAIN driver that you can get from the manufacturer of the device in order to capture your panoramic x-rays directly into your image management application.

Intraoral Cameras:

There are many intraoral cameras on the market. Many of the big “name brand” cameras will include direct integrations into many of the dental image management software applications. (This means a direct integration where the software doesn’t need a TWAIN. The device “speaks natively” with the imaging software). So, most cases don’t need the TWAIN “translator.” However, many if not most of the intra-oral camera manufacturers still create a TWAIN driver for their cameras. This ensures that they can easily integrate their camera with whatever image management software a practice may be using. Even if it is not one of the big-name ones.

Extraoral Cameras:

Just like the majority of digital cameras, few manufacturers of the SLR cameras gained popularity within the dental industry. Digital cameras were one of the initial devices that needed the TWAIN drivers, so all of them still have them. Now with image file formats more standardized, a device driver will often already install itself when you plug your digital camera into your computer. (Most cameras will save in a common file format which most computers can use natively) Alternatively, you can go to a disk/website for downloading and installing the device driver and the TWAIN.

However, you can access the common file format image files directly through navigating to the camera. And you can pull directly off of the camera and save to the computer. You could also navigate from your dental image management software to the camera and pull your patient’s images directly into their record. To need the TWAIN driver, you would have to capture the images “tethered” to the computer. This make the images would save to the patient record in real-time as you take them. Most doctors don’t like to have the cable connected to the computer while they are taking the SLR camera images. So make sure your workflow will really need a TWAIN or not.

Digital Intraoral Sensors:

Not all intraoral sensors will have a TWAIN driver created for them. Not all the interfaces of the sensor’s TWAIN will be the same either. Some have no interface to an extremely simple interface. They can only capture one image at a time and you would have to click the “acquire” button for every image that you need to capture. For other manufacturer’s TWAIN drivers, the interface has many different options, such as the TWAIN for the DentiMax Dream Sensor.

Types of Dental Image Capturing

There are different options for capturing a single image at a time or for capturing multiple images. These options all get saved in the TWAIN interface. Then all of the images can return at the same time. The selected options greatly depend on the calling application. Some image management applications adhere to and use more of the available functions in the TWAIN API than others. An image management application only allows the acquisition of one image at a time if that’s how it set up the TWAIN interface.

If the calling application allows for multiple images to return from the TWAIN all at once, then the interface can set up for this as well.

Some of the image management applications can even call a TWAIN interface for every tile in a series. This way it returns the image to that tile and calls the TWAIN for the next image in the series.

Unfortunately, this often becomes the exception rather than the rule. Most dental image management applications will either allow for the images to capture only one at a time. Or they require clicking “acquire” for every x-ray you needed in a series.

Or, they allow multiple images to return all at once. I have found that many of today’s dental image management applications allow for this type of image acquisition via TWAIN driver.

So you click acquire once and capture all of the images you need for your series in the DentiMax interface. Then you can click “stop capture” and “return images.” All the images return to the correct tiles and all stay oriented correctly.

Conclusion

Here’s probably more information than what you expected on what a TWAIN driver is. I felt that it was important to give some of the history and background to how the TWAIN came about rather than to jump into the dental specific devices.

TWAIN is really all about allowing any imaging device to “communicate” with any image application. Of course, some developers of TWAIN drivers adhere to the TWAIN standard more closely than others. Once in a great while you may run into a device that is quirky with your specific image management program. Usually though, they work great and are an excellent way for you to be able to use different devices in your image management software other than the specific device that the software came with.

For more information on how the DentiMax Dream Sensor works with our TWAIN driver in some of the various dental imaging applications out there, please read the articles I have written on using the DentiMax Dream Sensor specifically in the application that you are using. If you don’t see an article about the imaging software that you are using, please let us know! I will be happy to write an article on how to use the DentiMax Dream Sensors in your imaging software.

Jim Ramey holds a B.S. degree in management information systems from the University of Akron. Since 2003, he has worked exclusively with digital radiography technology and has experience with most sensors on the market, including digital, panoramic, cephalometric, and intraoral cameras.